A dual Johnny Warren Medal winner, a three-time A-League Champion, a two time A-League Premier, a two time Gary Wilkins Medal winner and the winner of the 2014 Joe Marston Medal, Broich is considered one of the greatest players in A-League history.[4] With 66 assists, Broich is the leading assister in A-League history.[5]

Broich played in several Bavarian youth teams such as ASV Rott am Inn, TSV 1860 Rosenheim and SpVgg Unterhaching. Later he played for the U23 team of Unterhaching and could have earned promotion to the Regionalliga Süd (Then Germany's 3rd league), but the manager did not include him in the first squad so he decided to leave. He signed a contract with SV Wacker Burghausen of the Regionalliga Süd and earned promotion to the 2. Bundesliga in 2002. During this time, he gained the reputation of a "thinking-man's player", being dubbed "Mozart" by his teammates, who often spotted him reading classic German literature and listening to classical music. With Burghausen, he became a standout midfielder and caught the eye of several top Bundesliga teams, including FC Bayern Munich.

In January 2004, he decided to sign with Borussia Mönchengladbach in the Bundesliga. Alongside Bastian Schweinsteiger and Lukas Podolski, Broich was considered to be the "bearer of hope" for the German national team and many media sources predicted that he would be a future player for the national team. However, he injured his foot in May 2004 and was unable to participate in the 2004 UEFA European Under-21 Football Championship with the German team. During his injury, he struggled with the pressure to represent his country, drawing comparisons between himself and Sebastian Deisler, another German national team player who in 2003 suffered depression as a result of enormous national pressure, eventually retiring from football.[6]

At the start of the 2004–05 season, Mönchengladbach fired manager Holger Fach and hired Dutch coach Dick Advocaat. Broich became a fan favorite and his jersey surged to the top-sold in the club's fan shop. However, Broich clashed on and off the field with his new manager, Advokaat criticising "Mozart's" lack of physicality and free-spirited style, even going as far to sending him down to play with the club's second team. Despite this tough period in the Bundesliga, Broich was called up to participate in the preliminary team for the 2006 World Cup, and after a standout match against Scotland, caught the attention of the national media, including future national team coach Jogi Löw. Advocaat was eventually fired, and Broich, under new trainer Horst Köppel, returned to the starting rotation, playing a large role in helping the team avoid relegation.[6]

During the season hiatus, Broich found out that his contract with Mönchengladbach would not be extended. Borussia Dortmund were very interested in signing Broich as a replacement for Tomáš Rosický, who had signed with Arsenal.[7] But it was rivals 1. FC Köln, hoping to bolster their squad to gain promotion from the second league to the Bundesliga, who were also strongly interested, who Broich signed with for the 2006–07 season. It was a season of ups and downs, with the highlight being a 4–2 DFB-Pokal win over Schalke 04, who at that time were ranked first in the Bundesliga. Broich scored the deciding goal in the 89th minute. However, back in the Second Bundesliga, he clashed with newly recruited coach Christoph Daum, who he felt was not giving him enough playing time. Köln gained promotion to the Bundesliga, but the relationship between player and coach never improved.

Broich again started to think about playing abroad, attempting to move to the Australian A-League with Adelaide United.[8] However, he was convinced by former Mönchengladbach assistant manager and Broich-fan Michael Oenning, who now had a head coach position with 1. FC Nürnberg, to join him on his new team. Broich signed a one-year contract on 9 June 2009, but, after an early season-injury, he had a slow start and considered giving football in Germany up for good. After only seven season caps, he completed his contract with Nürnberg and again began to look south to Australia.

On 11 May 2010, Broich signed a three.year deal with A-League club Brisbane Roar. He made his debut for the club against Everton in a pre-season Translink Cup game. He scored his first goal for the Roar in round seven against Adelaide United.[9] With six goals and 14 assists, Broich was instrumental in his debut season, which saw the Roar win their first ever Premiership and Championship.[10] Broich assisted both of Brisbane's goals in the grand final. It was his corner kick that assisted Erik Paartalu's last minute equaliser to send the final to a penalty shootout.

Broich won the Gary Wilkins Medal,[11] which is awarded to Brisbane Roar's player of the year and was runner up to Marcos Flores for the Johnny Warren Medal,[12] which is awarded to the A-League's player of the year. He finished the 2010–11 season with 12 assists, which was the highest in the league. Broich has only lost two A-League matches while playing for Brisbane, a 3–0 away loss to the Melbourne Victory on 12 September 2010 and a 1–0 home loss to the Newcastle Jets on 28 January 2012. In the 2011–12 season, Broich won the Johnny Warren Medal for player of the year and the A-League Foreign Player of the Year award.[13]

On 10 September 2012, it was announced that Broich had signed a four-year contract extension with the Roar, which means he is contracted to Brisbane until the end of the 2016–17 campaign.[14]

On the opening game of the 2014-15 season, Broich netted a free kick opening the scoring for Brisbane, despite eventually going down 2-1 to Adelaide. Brisbane's horrible start to the season was further hampered when Broich was sidelined for six weeks after undergoing ankle surgery. Broich scored again against Adelaide in the elimination final, dispossessing defender Dylan McGowan to level the scores at 1-1. However, Brisbane again went down 2-1.

On 19 April 2017, Broich announced that he would be leaving the Roar at the end of the season, ending a 7 year association with the club.[16]

Broich has exceptional footwork and vision.[17] Since his arrival in Australia, Broich has received praise for his footballing talents, some saying that he is the "best foreigner we've seen" in Australian football.[18][19][20] Brisbane coach Ange Postecoglou called Broich one of the best players in the A-League.[21] Broich is highly influential in the Brisbane Roar squad. When missing because of an injury, Roar managed to win only one in eight games, ending their record-breaking undefeated streak of 36 games.[22]

From 2002 to 2004, Broich played seven times for the Germany U-21. In 2004 and 2005, he was a member of the "Team 2006", a team that gives players a chance to play international friendlies to gain experience for a future in the national squad.